LED light flickering is caused by unstable power supply, usually due to low frequency (less than 50Hz), loose or faulty wiring, incompatible dimmer switches, or faulty LED components (such as a faulty driver). Unlike traditional bulbs, LEDs work "on" and "off", which means any interruption in the flow of electricity can cause visible flickering.
If you've replaced your old incandescent bulbs with LED bulbs and found that they flicker, you're not alone. This is a common problem, and more often than not, the bulbs themselves aren't the real culprit.
LED bulbs work much like computers, switching between on and off states quickly without any continuity. If the alternating current (AC) powering them fluctuates or fails, you may notice LED lights flickering as the LED lights struggle to maintain a steady flow of electricity.
Here are the most common reasons why LED bulbs flicker:
Low frequency: LEDs may flicker if the power supply frequency is less than 50Hz.
Wiring issues: Loose or incorrect wiring can interfere with the flow of electricity.
Incompatible dimmer switches: Not all dimmers are designed to work with LEDs, so they can cause flickering.
Faulty LED Components: Faulty LED drivers or internal components can cause flickering.
Since a flickering bulb can turn a space from brilliant to dingy in an instant, fixing the problem as quickly as possible is key to restoring normal lighting.
LED Bulb Flickering Without Dimmer
If the dimmer isn't faulty, flickering issues are usually due to one of three reasons:
Something is wrong with the LED bulb
The fault is in the wiring
The problem is with current regulations
Sometimes, the problem is caused by short wire lengths to the fixture. All wires should be at least 6 inches (about 15 cm) in length. You may also experience flickering issues if the wires connecting the bulb, switch, and fixture are loose.
Another culprit could be a faulty LED driver component. If the driver is of poor quality, it may not be able to withstand the constant heat generated by other LED components. If you like to take apart electronic components to check for faults, then you should check for bulging or swollen capacitors.
In addition to the fixture, check the switchboard. If the circuit breaker wiring is loose, you may also experience flickering issues.
Power factor should not be ignored either, as it is well known to cause flickering issues. For example, if you connect an LED bulb to the same circuit as an incandescent bulb, the LED bulb may flicker. This is because the incandescent bulb consumes 100% of the required energy - 60 watts in most cases - leaving the remaining power for the LED bulb and other appliances.
Two or three traditional bulbs will quickly use up all the power, leaving little power left for the LED bulb. This, in turn, causes the LED bulb to flicker due to the lack of available power.
Why do LED bulbs flicker on a dimmer switch?
As mentioned earlier, LED bulbs work "on" and "off". Older dimmers designed for incandescent bulbs, on the other hand, evenly vary the level of current supplied to the bulb. This is why LED bulbs may not perform as expected when using older dimmers.
Flickering may occur if the dimmer switch you are using is not compatible with the LED bulbs. In this case, the best thing to do is to upgrade your dimmer switch. Buy one that is designed specifically for LED bulbs.
While dimmable LED bulbs are more common than ever, not all LEDs are dimmable. Using a non-dimmable LED bulb with a dimmer switch can also cause flickering. If this is the cause of the problem, the solution is simple. You just need to replace the non-dimmable LED bulb with a dimmable one.
Why does an LED flicker when it is turned off?
You may see a flickering LED bulb when it is turned off. We are not talking about a faint afterglow that only lasts for 20-30 seconds or even a minute or two, but a full-blown flickering effect, or a dim light that stays on even after the switch is turned off.
What is going on? Is this a scam?
First of all: this is a common problem and there are no tricks. This situation is almost always related to smart switches.
These switches come with a range of additional features, such as WiFi control, dimmers, night lights, etc.
Such high-end switches always need some standby power to ensure that their smart features work properly. This is where the fault usually lies.
We will not go into too many technical details here, but some technical explanation is needed. If the circuit is not correct, the smart switch may not be able to use the neutral wire. Since your LED bulb is on the negative wire, capacitive coupling may occur, resulting in residual power left in the capacitor.
Due to current leakage and stray capacitance, enough voltage can build up in the circuit to cause an LED bulb to flicker or glow.
An easy way to test this is to use a one-touch tester. With the switch off, touch the tester to any of the connection points in the LED bulb holder. If there is stray capacitance and leakage current, the light will flicker.
How do I prevent or stop LED light flickering?
First, make sure the bulb is properly connected. Twist it a little to make sure nothing is loose.
If this doesn't fix the problem, try replacing it with another LED bulb. If everything works, then you can rest assured that the previous bulb was definitely at fault.
As mentioned above, capacitor swelling often causes flickering issues. So, instead of throwing out the old capacitor, replace the damaged one. This will not only extend the life of the LED bulb, but also solve the flickering problem.
However, if your new LED bulb also has flickering issues, check the dimmer. Is it compatible with your LED bulb?
You can check compatibility online by entering your existing dimmer switch and bulb model. If you have an old, incompatible dimmer, we recommend replacing it with a new one. Buy a dimmer that's compatible with LED bulbs and you may no longer have flickering issues.
If the problem isn't with the dimmer, maybe you should call an electrician